Printed circuit board (PCB) plug-in mounting shelves are well known. Such shelves are basically comprised of an enclosure into which one or more PCB's can be slidably inserted or removed for repair and a backplane having a multitude of pins therethrough which forms the backwall of the shelf. A connector affixed to one end of the PCB engages pins on the backplane once fully inserted into the enclosure. The pins are also electrically connected to other pins in the same shelf, other shelves and/or equipment remote from the shelves.
Each mounting shelf can accept a plurality of PCB's (e.g., up to 40) and the circuitry on each PCB may perform a different function than the others. Therefore, it is necessary to provide a physical coding scheme that will prevent the wrong PCB from being connected to the backplane. One such coding technique is to insert a keying member, comprised of a planar base member with plurality of pins or keys extending therefrom, onto the backplane within the array of pins into which the particular PCB is to be inserted. A portion of the connector on that PCB will have mating openings to receive only the properly coded arrangement of keys in the keying member on the backplane.
Such a coding technique has proved to be most effective in precluding the connection of improper PCB's into the backplane. Heretofore, the insertion of such keying members into the backplane has been done manually. Such manual operation requires that an operator reach inside the shelf, find the proper location, align holes in the substrate to the backplane pins and urge the keying members into place. Such an operation is time consuming, inefficient and can result in the insertion of keying members in the wrong position.
Accordingly, there is a need for a technique for accurately locating and inserting keying members into a backplane of a PCB mounting shelf.